Internal-combustion engine



y 1. o. w. LAVALLEE.

INTERNAL COMBUSTON ENGINE.

APPLICATION FlLED MAR-11,1920.

Patented May 10,1921.

Ilzl? fm1/m;- Jw @en UW JOSEPH o. w. LAVALLEE, or MONTREAL, QUEBEC, CANADA, AssreNoR'ro CARON 1 BROTHERS, OF MONTREAL, QUEBEC, CANADA. Y

Great Britainand Ireland,-residing"at the Y provements piston 2 reciprocates. The bearing 20` cast with the pistonv contains the wrist pin 4 to the city of .Montreal Dominion of Canada, have invented certain new and useful Imin Internal-Combustion Y Engines,'of which thefollowing is a specification.

This invention relates to improvements in internal combustionengines of the two stroke cycle type and more especially to double acting internal combustion engines in which the preliminary compression of the fuel mixture takes place within the piston.

The object of this invention is to provide anengine of the above type, of simple and compact construction in which an explosive impulse is given alternatelyat each end `of' the cylinder to. every revolution of thefcrank shaft, and a charge of fuel mixture is taken into one'end of the piston `and is compressed in time to pass into the adj acentV end of the cylinder at the end of each stroke.

A further object of this invention is to provide -a means of adjusting the pressure of the preliminary Vcompression and of relieving the load of the preliminary. cornpression. i Y Y A further object of this invention is to provide an engine of the kabove type in which stuiling boxes are notl required in thecylin der or piston,'and in which there'are no small moving parts within. the cylinder which are liable to require adjustment or res placement. e Y

The drawings hereto annexedY will `illustrate one form of an engine in accordance with' my invention.

In Figure 1 a vertical section at'right an-V gles to the crank shaft is shown; l y

Fig. 2 shows a verticalsection through the axis `of the'crank shaft. l' y i The double ended cylinder 1 is water jacks etedkat both ends. Y

, It is-preferably constructed in three separable parts, the two end portions being se cured to` the central4 portion by means of suitable studs 27. A Within this cylinder lthe double ended endsj of which are secured the connecting i Specification of Letters Patent.

Patented May ie, 192i.

` Application led March 11, 1920. Serial No. 365,066.

rods 15 outside the cylinder 17 slots 21 being provided in the walls of the cylinder 1.

The connecting rods 15 are'preferably cast integral with thebearing sleeve 151 in which the crank pin rotates.`

Within thepiston 2 and secured to the Vcylinder 1 by the pins 6 is the double ended central member 3. The walls ofl this central member 3 are slotted at 5 to allow the bearingy 2O of thepiston 2 to reciprocate. This slottedportion is inclosed as shown in F ig. 1,- by the diaphragms 24, which *provide cup shaped ends to the central member 3. vThe walls of this central member cover ySuitable baffles 12 on therends ofthek the area where the by-pass y piston surround opens.

- Inlet ports 9 in the cylinder walls shown the slots 14 during the reciprocation of the l adjacent to the exhaust ports 8, are connect- Y Y ed with the carbureter and fuel feed in the usual manner.

The piston is provided with inlet ports 13 which register with the inlet ports of the cylinder at theend of, each stroke as appears in thelower half of Fig; 1 thereby` feeding the interior of the piston end and cup portion of .the central member 3 with the fuel mixture when that area is at its greatest exten Y The outlet port 11 in' the piston wall meets the by-pass 10 toward the end'of the strokewhereby the charge of fuel mixture now compressed within the end of the Vpiston passes'through the by-pass into the cylinder endwhich it fills as the exhaust clears the cylinder of the burnt gases.

In addition-to the by-pass 10 there may be provided a port 25 leading to a'tank 26,

eoi

the object of which will be set forth herev inafter. y

Suitable kpiston rings or packing 22 are providedl near the ends oftheV piston walls and the like are provided at 23 near. the ends of the central member 3.

i' pio pacities. the best feed pressure for obtainingk The crank shaft 17 is journaled in bearyings 18 supported'by the frames 19. VThe lcranks 16 in thefunitas shown are cast with compensating lugs as'shown in Fig.l2.

' rigidity and .strength are provided with simple compact and light niembers.

rllhe function of the tank 26 is twofold.

In the'irst place when the port 11 reaches the by-pass 10 the compressed' mixture will -iill the tank thereby reducing the pres` y sure `,within the piston and preventing the cushioning effect toward the end of the piston stroke? By usingtanks of various ca- I. high efliciency can readily be discovered for any sizeengine.`

In the second place with a port28 in the s pistonV opening into the by-pass 10 opposite klv30 the intake port 13, an increased quantity of fuelmixtu-re can be taken into'the'engine at each stroke; i 'f y i* In describing the operation of this inven- 'f tion and startingfrom in Figs. 1 and 2,V

The piston `is-atther-lowest limit ofits y travel and the crank is at itsdead center.

The lower pend of the "cylinder is charged' with fuel mixture under secondary compressionl and isV ready for ignition from the vrrArscthe port. 13 in'k this endof the piston s' registerswith the lower inlet port 9 afresh charge of theinixture enters the pistoniilling the area between the diaphragm 24; and theend of the piston withvthe mixture.

,The upper end of the piston is shown as uncovering the exhaust port `8 and the by-l fpass 10 kin which portion the exhaust gases are vac-ating the-cylinder and the mixture.

.registers with the by-pass 1().r

under' preliminary` pressureY takes their place, passingpfroni within the upper end of the piston through.,V the port k11 which now .QI-Lifter ignition of the lowercharge the Y e upperend of the cylinder is` gradually comy piston begins to ascend', closing the upper .50 t l v and `the lower fuel feed port 18.

exhaustgport 8 and also the' upper by-pass Ythe f Proceeding to Vascend the charge in pressedl as isfalso the fresh charge in the lower end` ofthe piston while ,the residue of the mixture in the upper end of the piston'v is expanded and vforms axpartial vacuum.`

, When thefpiston reaches the upperliniit Y e of its strokegthe position is the reverse of mixture` under high compressiony "and the partial vacuum in the upper end of the pisthe positiony shown i gases pass out of the lower exhaust port.

It will be seen therefore that while the crank shaft is completing one revolution two charges have been taken in to the piston and compressed primarily two charges have beenfurther compressed and exploded and two impulses given tothe crank shaft through the `connecting. rods.

1, InA an internal combustion engine of the two cycle type, a double ended piston journaled to connecting rods outside the cylinder, and a central' cylindrical stationaryfineinber within the'piston, secured to the'c'ylinder walls by retaining pins through slots in the piston walls, adapted to forin compression `chambers as described. f

2. Inv an engine of the type specified ay central cylindrical stationary member within the piston secured to the cylinder walls and having an inclosed slot therethrough in which the wrist pin of the piston reciprocates. i

' 3. Inan engine of the type specified, the combination of a cylinder, a double ended pistontherein, with slotted walls, a central stationary member secured to the cylinder by `retaining pins which passk through the slots'in the piston, transverse slot through the stationary member, in which a wrist pinl journaled inthe piston isadapted to reciprocate. '1,

4. In-an engine of the type specified, the combination of a double L ended cylinder with slotted walls,`a double ended piston with slotted walls and having a central transverse bearing, a central stationary membersecured tothe cylinder walls with an inclosed transverse slot therein, and Ia ywrist `pin' journaled in the said. transverse and journaled tothe crankof a crankshaft,

a central cylindrical stationary member',

having cup shaped ends, secured to thec'ylinder wallsxby retaining pins Whichfpass Y Y through the slots in the pistonwalls and thatshown in Figs. 1 and 2. The upper'end ofthe cylinder is now charged with fuel an inclcsed slot through said'stationary member adapted to permit saidsleeve an wrist pin to ireciprocatetherein. Y, VIn an engine of they type' 4specified the combinationl fof ra' jdouble ended cylinder with central longitudinal slots in its walls which have also suitable inlet and exhaust ports, a Vdouble ended Ypiston therein having `Wrist pinY journaled in said sleeve and reciprocating in the slots of the cylinder Walls,

connecting rods secured to the end of the said Wrist pin outside the cylinder Walls and journaled to the crank of a crank shaft by means of a connecting sleeve, a central cylindrical stationary cylindrical memberV having diaphragms forming cup shaped ends, and slotted sides between the diaphragms, the Walls adapted to receive rctaining pins, which pinsare secured to the cylinder Walls and'pass through slots in piston Walls. Y

7. In an engine of the type specified the combination of a central cylindrical stationary member having an inclosed transverse slot therein, with a double ended piston thereabout having a transverse sleeve central thereto and adapted to reciprocate in said slot, which sleeve forms the bearing of a Wrist pin and connecting rods secured to the wrist pin and journaled to the crank of the crank shaft. p

8. .In an engine of the type specified, a by-pass in the cylinder ,Wall registering With a port in the piston Wall, a storage tank adjacent to the by-pass With an opening vtherefrom adapted to receive the fuel mixture compressed Within the piston and to supply it to the cylinder. f Y

9. In an :internal combustion engine a double ended cylinderk with slotted walls a double ended piston, a Wristpin journaled in piston, the ends of which pin project through cylinder slots, and connecting rods connected by an integral crank sleeve, secured to the'ends of the wrist pin, in 4combination with a central cylindrical stationary member Within the piston and secured to the cylinder.

- 10. In an' internal combustion engine a cylinder havingA heads at opposite endsV forming combustion chambers, a hollow piston havingheads at opposite ends formlng compression chambers, a dlametrical Wrlst pin secured toconnecting rods outside the cylinder, journaled in the. piston and prober secured to the cylinder by retaining pins Which pass through slots in the piston Walls, and having an inclosed slot in Which th Wrist pin reciprocates. a

11. In an yengine of the type specified, a central cylindrical stationary member inside the piston, secured to the cylinder Walls, having an inclosed transverse slot therein and cup shaped ends asY described. f

12. In an engine of the type specified, a central cylindrical stationary member secured Within the piston to the cylinder Walls through slots in the piston Walls, adapted to cover such slots during the reciprocation of the piston.

13. In an engine of the class specied, a central cylindrical stationary member c having cup shaped ends and' an inclosed transverse slot in Which the Wrist pin and sleeve of piston reciprocate, secured to the cylinderrby retaining pins through slots in the piston Walls and adapted to cover such slots yduring the'reciprocation of the piston.

14. In an' engine of the type specified, a double ended piston anda central stationary member therein, having an inclosed transverseslot-and cup shaped endsv adapted to form compression chambers with the ends of the piston. n Y Y yIn Witness whereof, I have signed this specification. c c

J.YO. LAVALLEE.

jecting through slots in the cylinder walls, and a central cylindrical stationary mem- 

